Go Back   IceInSpace > Equipment > Astrophotography and Imaging Equipment and Discussions

Reply
 
Thread Tools Rating: Thread Rating: 3 votes, 5.00 average.
  #61  
Old 06-04-2012, 10:57 PM
tornado33
Registered User

tornado33 is offline
 
Join Date: Jan 2005
Location: Newcastle, NSW, Australia
Posts: 3,931
What would really interest me is a MONOCHROME sensor equipped Canon camera, I.E. a bog standard EOS DSLR without the colour bayer filter and with no IR cut filter at all. In theory it should be no dearer than a normal camera but its wishful thinking such a camera would be made I think.

Seeing as how the EOS sensors work as well as they do at room temeprature, a monochrome 18 MP cooled EOS camera would blow every dedicated astro camera out of the water as far as dark current noise went.

Then I once used the GRAS (now Itelescope) online scopes, the raw light frames still had some dark current noise, which was easy to subtract as they also sent me a master dark from darks at the same temperature. However when I borrowed Houghys cooled DSLR the noise, or rather lack of it even on the raw light frames was mind boggling. The only thing that stops them from cornering the astro camera market is they are colour not monochrome chips.

Look at what cooling an EOS sensor does. That, in monochrome with accurate temperature control would be absolutely brilliant. You could do 1 hour subs with hardly any noise. Remember as a guide the Central DS 600d "only" cools to 28 deg below ambient yet returns stunningly dark darks that have to be heavily stretched to show noise.
Scott
Reply With Quote
  #62  
Old 07-04-2012, 12:28 AM
MrB's Avatar
MrB (Simon)
Old Man Yells at Cloud

MrB is offline
 
Join Date: Jan 2007
Location: Rockingham WA
Posts: 3,408
Quote:
Originally Posted by rogerg View Post
Locally, PRA have announced you can pre-order it.
Cheers Roger, looks like I might have to lift my decade long boycott of PRA.
Reply With Quote
  #63  
Old 07-04-2012, 11:39 AM
danielsun's Avatar
danielsun
Canon collector

danielsun is offline
 
Join Date: Oct 2005
Location: Taylors Lakes Melb
Posts: 1,965
Dohh!! I only just ordered the 7D last week and had no idea they where releasing this Astro dedicated 60Da but think it's great that they have considered this side of Photography.
Looking forward to reading the reviews and am wondering if it is more than just removing the filter.

Cheers Daniel.
Reply With Quote
  #64  
Old 07-04-2012, 01:05 PM
trek1701's Avatar
trek1701 (Mark)
Registered User

trek1701 is offline
 
Join Date: Jan 2009
Location: Melbourne
Posts: 200
Quote:
Originally Posted by danielsun View Post
Dohh!! I only just ordered the 7D last week and had no idea they where releasing this Astro dedicated 60Da but think it's great that they have considered this side of Photography.
Looking forward to reading the reviews and am wondering if it is more than just removing the filter.

Cheers Daniel.


Hi Daniel

If you only just ordered it, you should be able to change the order without any penalty.

Cheers Mark
Reply With Quote
  #65  
Old 07-04-2012, 01:12 PM
2stroke's Avatar
2stroke (Jay)
The devil's advocate

2stroke is offline
 
Join Date: Jul 2011
Posts: 816
Quote:
Originally Posted by tornado33 View Post
What would really interest me is a MONOCHROME sensor equipped Canon camera, I.E. a bog standard EOS DSLR without the colour bayer filter and with no IR cut filter at all. In theory it should be no dearer than a normal camera but its wishful thinking such a camera would be made I think.

Seeing as how the EOS sensors work as well as they do at room temeprature, a monochrome 18 MP cooled EOS camera would blow every dedicated astro camera out of the water as far as dark current noise went.

Then I once used the GRAS (now Itelescope) online scopes, the raw light frames still had some dark current noise, which was easy to subtract as they also sent me a master dark from darks at the same temperature. However when I borrowed Houghys cooled DSLR the noise, or rather lack of it even on the raw light frames was mind boggling. The only thing that stops them from cornering the astro camera market is they are colour not monochrome chips.

Look at what cooling an EOS sensor does. That, in monochrome with accurate temperature control would be absolutely brilliant. You could do 1 hour subs with hardly any noise. Remember as a guide the Central DS 600d "only" cools to 28 deg below ambient yet returns stunningly dark darks that have to be heavily stretched to show noise.
Scott
Will say the tests of this gens sensors are mind blowing, I think next gen even without cooling EOS cameras will give dedicated astro cameras one hell of a run while even un-cooled. Technology is catching up and it won't be long before it gets hard to justify the pricing of of astro cams. With hacked firmware like magic lantern http://http://magiclantern.wikia.com/wiki/Magic_Lantern_Firmware_Wiki , DIY filter modding and cooling its really putting out of reach dedicated astro cams into all peoples hands and its great
I've just done a 1100D filter mod myself and can't wait to play with some cooling Magic lantern is currently in development for 1100D support which will crack the iso limits right open on this baby Hmm will be waiting to see if canon has any firmware changes on the 60Da myself, though i think this will be doubtful, it could open up some a ton of firmware in the AP world. BTW that link to pre-modded cooled cameras is great bud
Reply With Quote
  #66  
Old 07-04-2012, 01:42 PM
spacezebra's Avatar
spacezebra (Petra)
Lost in Namibia

spacezebra is offline
 
Join Date: Aug 2005
Location: Albury NSW
Posts: 3,097
Getting excited

Cheers Petra d.
Reply With Quote
  #67  
Old 07-04-2012, 02:07 PM
g__day's Avatar
g__day (Matthew)
Tech Guru

g__day is offline
 
Join Date: Dec 2005
Location: Sydney
Posts: 2,564
Should have looked in this forum first! From my read its an Astronomik IR filter. I've send many letters to Canon research for DSLRs over the past few years, refering them to Badder, Hutech and Astronomik IR filters. Slightly surprised they went the Astronomik route, I'll see if I can find out why.

The other idea I suggested was a user specified Liveview and Remote Live view settings for 1/10 sec up to 30 seconds. I think it was software locked to 3 frames per seconds, but there was no reason why a user couldn't verfiy this for hobby shots that required more signal from loner exposures. Wonder if Canon handled this?

Meanwhile just delighted this model has turned up!

Last edited by g__day; 07-04-2012 at 02:32 PM.
Reply With Quote
  #68  
Old 07-04-2012, 02:51 PM
danielsun's Avatar
danielsun
Canon collector

danielsun is offline
 
Join Date: Oct 2005
Location: Taylors Lakes Melb
Posts: 1,965
Quote:
Originally Posted by trek1701 View Post
Hi Daniel

If you only just ordered it, you should be able to change the order without any penalty.

Cheers Mark
Bought it on the net. Checked with them on Thursday, payment has gone through and it's well on it's way but that's ok, still very happy with the features of the 7D. Will wait and checkout the reviews of the 60Da and may end up also getting one down the track.

Cheers Daniel.
Reply With Quote
  #69  
Old 07-04-2012, 04:00 PM
Terry B's Avatar
Terry B
Country living & viewing

Terry B is offline
 
Join Date: Mar 2006
Location: Armidale
Posts: 2,761
Quote:
Originally Posted by Octane View Post
Things have come a long way since the 20Da in terms of sensor and high ISO characteristics.

Where you would be loathe to push past ISO-800 on the 40D, you can comfortably image at ISO-1600 on this newer camera, halving your exposure time.

In today's crappy weather, this is a windfall.

H
For astro imaging, why does a high ISO make any difference?
All it does is change the in camera amplification ie the gain of the CCD. This potentially reduces the dynamic range of your image. All astro photos should really be taken as RAW and amplified if needed afterwards anyway.
Reply With Quote
  #70  
Old 07-04-2012, 04:06 PM
wasyoungonce's Avatar
wasyoungonce (Brendan)
Certified Village Idiot

wasyoungonce is offline
 
Join Date: Jul 2006
Location: Mexico city (Melb), Australia
Posts: 2,312
Jeezz...maybe a cooled spectrum modded camera from central DS is a better option.... 1100D or 600D.

Of course this in the price territory of an KAF 8300 OSC...although more pixels.
Reply With Quote
  #71  
Old 07-04-2012, 04:18 PM
2stroke's Avatar
2stroke (Jay)
The devil's advocate

2stroke is offline
 
Join Date: Jul 2011
Posts: 816
Quote:
Originally Posted by g__day View Post
Should have looked in this forum first! From my read its an Astronomik IR filter. I've send many letters to Canon research for DSLRs over the past few years, refering them to Badder, Hutech and Astronomik IR filters. Slightly surprised they went the Astronomik route, I'll see if I can find out why.

The other idea I suggested was a user specified Liveview and Remote Live view settings for 1/10 sec up to 30 seconds. I think it was software locked to 3 frames per seconds, but there was no reason why a user couldn't verfiy this for hobby shots that required more signal from loner exposures. Wonder if Canon handled this?

Meanwhile just delighted this model has turned up!
Well there own in house Low pass filter does a better job then any IR cut in the digi 4's from my reading and first hand experience. It wouldn't surprise me if there just using a astronomik MC clear, as the LP is an IR cut and gives a better spectrum then any of these filters. If they have gone for astronomik it will be for price and being able to fill there demand. Anyhow this if from what I know and understand, I could be total wrong

Umm liveview vai EOS utils works fine here for my 1100D's on whatever is set it for, maybe you should try updating EOS utils from canon. From the camera try updating the firmware from canon, if not flash with magic lantern which I would have done when i got the thing, canons firmware is n00b locked
Reply With Quote
  #72  
Old 07-04-2012, 09:37 PM
g__day's Avatar
g__day (Matthew)
Tech Guru

g__day is offline
 
Join Date: Dec 2005
Location: Sydney
Posts: 2,564
2Stroke - I don't have any Canon's with LiveView, I merely fired some questions to Canon Research (CiSRA) to ask if LiveView frame per second was alterable to make really long duration shots in low light - and was told no, it didn't go below 3 frames per second (user configurable). I explained how for astrophotography this option might be a boon when framing shots.

Are you saying there are utilities (Canon or 3rd party) that will allow you to determine how long each frame in Remote LiveView may be (and /or to up their gain / gamma)?
Reply With Quote
  #73  
Old 07-04-2012, 10:00 PM
CometGuy's Avatar
CometGuy
Registered User

CometGuy is offline
 
Join Date: Feb 2005
Location: Brisbane
Posts: 942
Quote:
Originally Posted by tornado33 View Post
What would really interest me is a MONOCHROME sensor equipped Canon camera, I.E. a bog standard EOS DSLR without the colour bayer filter and with no IR cut filter at all. In theory it should be no dearer than a normal camera but its wishful thinking such a camera would be made I think.

Seeing as how the EOS sensors work as well as they do at room temeprature, a monochrome 18 MP cooled EOS camera would blow every dedicated astro camera out of the water as far as dark current noise went.

Then I once used the GRAS (now Itelescope) online scopes, the raw light frames still had some dark current noise, which was easy to subtract as they also sent me a master dark from darks at the same temperature. However when I borrowed Houghys cooled DSLR the noise, or rather lack of it even on the raw light frames was mind boggling. The only thing that stops them from cornering the astro camera market is they are colour not monochrome chips.

Look at what cooling an EOS sensor does. That, in monochrome with accurate temperature control would be absolutely brilliant. You could do 1 hour subs with hardly any noise. Remember as a guide the Central DS 600d "only" cools to 28 deg below ambient yet returns stunningly dark darks that have to be heavily stretched to show noise.
Scott
Hi Scott,

A monochrome option already exists - there are a number of Kodak 8300 CCD cameras available and now the Sony 694 Exview II sensors. I have seen some of these go for very good prices here on IIS.

Terry
Reply With Quote
  #74  
Old 08-04-2012, 01:38 AM
2stroke's Avatar
2stroke (Jay)
The devil's advocate

2stroke is offline
 
Join Date: Jul 2011
Posts: 816
Quote:
Originally Posted by g__day View Post
2Stroke - I don't have any Canon's with LiveView, I merely fired some questions to Canon Research (CiSRA) to ask if LiveView frame per second was alterable to make really long duration shots in low light - and was told no, it didn't go below 3 frames per second (user configurable). I explained how for astrophotography this option might be a boon when framing shots.

Are you saying there are utilities (Canon or 3rd party) that will allow you to determine how long each frame in Remote LiveView may be (and /or to up their gain / gamma)?
hmm think your right on that one just tinkering now and exposure is doing squat :/ Lol i've never noticed , ill keep playing when i get a chance. I just up the iso to 400 when in live veiw.
Reply With Quote
  #75  
Old 08-04-2012, 02:10 AM
luigi
Registered User

luigi is offline
 
Join Date: Jun 2010
Posts: 438
Quote:
Originally Posted by Terry B View Post
For astro imaging, why does a high ISO make any difference?
All it does is change the in camera amplification ie the gain of the CCD. This potentially reduces the dynamic range of your image. All astro photos should really be taken as RAW and amplified if needed afterwards anyway.
The Signal to Noise ratio improves as you increase the ISO. This is because the sensor read noise is not amplified as the signal is.

So as long as the dynamic range is enough you should shoot at the highest possible ISO for a given exposure time.

For most DSLRs this stops making sense beyond ISO1600 but up to 1600 the higher the better.
Reply With Quote
  #76  
Old 08-04-2012, 08:13 AM
Terry B's Avatar
Terry B
Country living & viewing

Terry B is offline
 
Join Date: Mar 2006
Location: Armidale
Posts: 2,761
Quote:
Originally Posted by luigi View Post
The Signal to Noise ratio improves as you increase the ISO. This is because the sensor read noise is not amplified as the signal is.

So as long as the dynamic range is enough you should shoot at the highest possible ISO for a given exposure time.

For most DSLRs this stops making sense beyond ISO1600 but up to 1600 the higher the better.
I would have thought that astro photos all have a very high dynamic range. The difference in brightness of stars compared to DSO objects is very high. As long as you are happy losing almost all of the colour data for stars then I suppose this is ok.
I'm also curious about the read noise.
When is the gain (or ISP amplification) applied?
I thought that the order was that each line of the ccd is read then the gain is applied. This would mean that the read noise is also affected by the gain.
Reply With Quote
  #77  
Old 08-04-2012, 12:28 PM
trek1701's Avatar
trek1701 (Mark)
Registered User

trek1701 is offline
 
Join Date: Jan 2009
Location: Melbourne
Posts: 200
Iíve been told that you should use Liveview at least as possible (even though you need it to achieve actuate focus) because it increases noise, is this info correct???


Cheers Mark
Reply With Quote
  #78  
Old 08-04-2012, 01:27 PM
luigi
Registered User

luigi is offline
 
Join Date: Jun 2010
Posts: 438
Quote:
Originally Posted by Terry B View Post
I would have thought that astro photos all have a very high dynamic range. The difference in brightness of stars compared to DSO objects is very high. As long as you are happy losing almost all of the colour data for stars then I suppose this is ok.
I'm also curious about the read noise.
When is the gain (or ISP amplification) applied?
I thought that the order was that each line of the ccd is read then the gain is applied. This would mean that the read noise is also affected by the gain.
The DSLRs use CMOS not CCD
You have a wonderful explanation here:
http://theory.uchicago.edu/~ejm/pix/...ise/#readnoise


Quote:
Originally Posted by trek1701 View Post
Iíve been told that you should use Liveview at least as possible (even though you need it to achieve actuate focus) because it increases noise, is this info correct???
Cheers Mark
This is true, live-view increases thermal noise. So I use it to focus, frame and then turn it off for the rest of the night.
After about 1 minute of live-view you need 8 minutes off for the sensor to be back at the temperature it started.
Reply With Quote
  #79  
Old 08-04-2012, 01:32 PM
mithrandir's Avatar
mithrandir (Andrew)
Registered User

mithrandir is offline
 
Join Date: Jan 2009
Location: Glenhaven
Posts: 4,161
Quote:
Originally Posted by luigi View Post
The DSLRs use CMOS not CCD
Not quite true Luigi. For example my Sony has a CCD, and other manufacturers use the same Sony chip.
Reply With Quote
  #80  
Old 08-04-2012, 07:18 PM
luigi
Registered User

luigi is offline
 
Join Date: Jun 2010
Posts: 438
Quote:
Originally Posted by mithrandir View Post
Not quite true Luigi. For example my Sony has a CCD, and other manufacturers use the same Sony chip.
Yup but we are talking about the 60d here.
My stellar was not very writing but the sensor CMOS 60da is a
Reply With Quote
Reply

Bookmarks

Thread Tools
Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT +10. The time is now 11:12 AM.

Powered by vBulletin Version 3.8.7 | Copyright ©2000 - 2019, Jelsoft Enterprises Ltd.
Advertisement
EQ8-R
Advertisement
Astromechanics
Advertisement
Lunatico Astronomical
Advertisement
OzScopes Authorised Dealer
Advertisement
Bintel
Advertisement
Star Adventurer
Advertisement
Celestron RASA
Advertisement
Astronomy and Electronics Centre
Advertisement